The goal of this project is to study Aleutian disease virus (ADV), a non-defective parvovirus, that causes a persistent infection of mink associated with immune complex disease. Studies on ADV DNA have defined a double stranded (ds) ADV DNA intermediate that should prove suitable for restriction enzyme analysis of the viral genome and molecular cloning. Studies on ADV proteins have revealed that a 71,000 dalton nonstructural protein (p71) as well as the two major structural proteins (MW 85,000 (p85) and 75,000 (p75)) were immunoprecipitated by sera from mink with progressive AD. p71 was not immunoprecipitated by heterologous antisera, monoclonal antibodies prepared against purified ADV, or some sera from mink with nonprogressive disease. The role of this protein in the genesis of immune complexes is under study.